An assessment of the polar HOx photochemical budget based on 2003 Summit Greenland field observations

first_imgAn interpretative modeling analysis is conducted to simulate the diurnal variations in OH and HO2 + RO2 observed at Summit, Greenland in 2003. The main goal is to assess the HOx budget and to quantify the impact of snow emissions on ambient HOx as well as on CH2O and H2O2. This analysis is based on composite diurnal profiles of HOx precursors recorded during a 3-day period (July 7-9), which were generally compatible with values reported in earlier studies. The model simulations can reproduce the observed diurnal variation in HO2 + RO2 when they are constrained by observations of H2O2 and CH2O. By contrast, model predictions of OH were about factor of 2 higher than the observed values. Modeling analysis of H2O2 suggests that its distinct diurnal variation is likely controlled by snow emissions and loss by deposition and/or scavenging. Similarly, deposition and/or scavenging sinks are needed to reproduce the observed diel profile in CH2O. This study suggests that for the Summit 2003 period snow emissions contribute similar to 25% of the total CH2O production, while photochemical oxidation of hydrocarbon appears to be the dominant source. A budget assessment of HOx radicals shows that primary production from O(D-1) + H2O and photolysis of snow emitted precursors (i.e., H2O2 and CH2O)are the largest primary HOx sources at Summit, contributing 41% and 40%, respectively. The snow contribution to the HOx budget is mostly in the form of emissions of H2O2. The dominant HO, sink involves the HO2 + HO2 reaction forming H2O2, followed by its deposition to snow. These results differ from those previously reported for the South Pole (SP), in that primary production of HOx was shown to be largely driven by both the photolysis of CH2O and H2O2 emissions (46%) with smaller contributions coming from the oxidation of CH4 and the 0(D-1) + H2O reaction (i.e., 27% each). In sharp contrast to the findings at Summit in 2003, due to the much higher levels of NOx the SP HO, sinks are dominated by HOx-NOx reactions, leading to the formation and deposition of HNO3 and HO2NO2. Thus, a comparison between SP and Summit studies suggests that snow emissions appear to play a prominent role in controlling primary HOx production in both environments. However, as regards to maintaining highly elevated levels of OH, the two environments differ substantially. At Summit the elevated rate for primary production of HOx is most important; whereas, at SP it is the rapid recycling of the more prevalent HO2 radical, through reaction with NO, back to OH that is primarily responsible.last_img read more

Saint Mary’s promotes immigration awareness

first_imgSaint Mary’s La Fuerza, a club representing Latina culture on campus, is holding Action week in order “to create awareness about the realities of immigration in the U.S.,” said club vice president Brianda Salas, a sophomore. The first event held Monday was a viewing of the film “Papers,” which is “a documentary about undocumented youth and the challenges they face as they turn 18 and graduate high school without legal status,” Salas said.The week will continue with a bilingual mass in Le Mans Hall’s Holy Spirit Chapel at 9 p.m. Wednesday.On Thursday, La Fuerza will host Immigration Monologues, which will be “a short presentation about the myths and facts about immigration, followed by the real-life stories of individuals who have gone through the struggles of life as an immigrant and other similar stories,” Salas said.Salas said La Fuerza will also host guest speaker Enrique Morones, the founder of Border Angels.Salas said Border Angels is a non-profit organization made of volunteers who work to stop unnecessary deaths of individuals who travel through the Imperial Valley dessert areas and the mountain areas surrounding San Diego County.Morones will deliver a lecture on Tuesday at 7 p.m. in the Vander Vennet Theater. Though the lecture will not be part of Action Week, it is related to its message, she said. “We believe that by bringing Enrique Morones, it will enhance the Saint Mary’s College mission of commitment for social justice as well as promote student activism,” Salas said. “We not only wish to raise awareness, we want to promote action.”Salas said she hopes these events will help break down existing stereotypes and misconceptions about immigration.“La Fuerza wants to dispel those myths by presenting facts and real-life stories that will draw our audience closer to the realities of immigration and how it affects everyone and anyone regardless of migratory status,” Salas said.The week as a whole is only part of the group’s mission to bring knowledge to campus about Latina Culture.“As a group, we want to promote diversity and cultural education on our campus and the community,” Salas said. “With this event, we believe we are doing just that, educating the campus on immigration not just through opinions but facts.”Salas said the club does not discriminate and embraces all cultures and backgrounds. “We welcome anybody, not just Latinas,” Salas said. “Everyone is welcomed to become a member of La Fuerza and share their uniqueness through La Fuerza.”last_img read more

17 quirky ways to save extra money this summer

first_img 28SHARESShareShareSharePrintMailGooglePinterestDiggRedditStumbleuponDeliciousBufferTumblr With the hype around spring cleaning and beach ready bodies, it’s time to give our personal finances some seasonal love. With longer days, better weather and relaxed attitudes, summer is a great time to amp up the mindfulness and institute some savvy habits. Here are a few ways to beef up your bank account by September.1. Traveling internationally? Check your cards.Thanks to a strong dollar and low gas prices, international travel is cheaper than ever. And it seems that Americans are catching on. A new survey by Synchrony Financial  found that more Americans are planning on  traveling in 2016 because of lower gas prices.Take advantage of this perfect storm and book now. But before you go, make sure you have at least one credit card with no foreign transaction rates. With the variety of cards available that offer no fees, there is no need to be paying an extra 1 to 3 percent per transaction. continue reading »last_img read more

Mbappe Question Mark

first_imgMbappe, the new kid on the block, could well do a Renato Sanches in 12 months.Money bags, Paris Saint-Germain proved there is no stopping them in their bid to flex their financial muscles with the season-long loan signing of French wonder-kid Kylian Mbappe.Reports suggested the French giants only negotiated a loan deal with Monaco in order not to flout UEFA Financial Fair Play (FFP) regulations. In a summer where the capital club spent a world record £198million transfer fee on Neymar, there was no limit to their spending power when they earmarked Mbappe as the next big acquisition, a £165.7million transfer which becomes activated next summer.The prospects of Neymar and Mbappe lining up in PSG’s new formed attack, leaves even the fiercest rivals grinning with admiration. Considering this is a season preceding the FIFA World Cup, Mbappe’s decision could cost him a place in the eventuality of Le Bleu progressing to the tournament in Russia.The burden of potentially being the second most expensive player in football history could be too much to handle for the 18-year-old teenage sensation. A bad season with the Parc des Princes outfit could well have PSG having a rethink about an agreement made in the summer.For the avoidance of doubt, football player’s careers quickly go south, in an era where the beautiful game appears to have lost its true value.Renato Sanches is a typical example of an exciting young talent, whom so much was expected of following his 2016 transfer from Benfica to Bayern Munich for an eye-popping 85m euro!The then 18-year-old (coincidentally Mbappe’s present age) was regarded as the next big thing in world football, and even turned down a move to Manchester United in favour of a switch to the Bavarian giants.A month after the completion of his big money transfer to Germany, he was a European Championship winner with Portugal, his first major tournament at senior international level, been selected Young Player of the tournament.Sadly, Sanches struggled for form in his new task and environment, though it must be noted he arrived Bayern Munich injured.From the above analysis, Mbappe could well have been suited to spend an extra season at Monaco, play with less pressure, familiar teammates and environment, which potentially aids his overall football development and thereafter proceed to make magic at a major European heavyweight other than PSG!RelatedBREAKING: PSG Signs Kylian Mbappe From MonacoAugust 31, 2017In “Europe”VIDEO: PSG Unveils Kylian MbappeSeptember 6, 2017In “France”Zinedine Zidane Expresses Interest In Working With Kylian MbappeMarch 15, 2019In “Spain”last_img read more